a famous diy'er saying "while I'm in there"
I would replace the belts too if they have not been.
Change all the coolant hoses - they are the ones that can do the most damage if they let go and I'm not just talking about getting the Nike's wet. The coolant should get changed when the hoses are refreashed. The vacuum hoses should come next but you can let them fail. They will cause problems that won't really leave you by the road.
You inquired about the importance of the various hoses, the coolant hoses are the most important. The most important coolant hose on the car is the one that goes bad and leaves you by the road or worse, by the road with a severely overheated engine. It is not something you want to happen.